How can caffeine help migraines?

June 29, 2010|By Dr. Edward Wolpow

Q. If coffee constricts blood vessels, why would it help migraine sufferers, since the constriction curtails blood flow, which would seem to cause more pain?

A. The simple notion that migraines are caused by the expansion of blood vessels (vasodilation) on the surface of the brain is, well, too simple. Migraines are complicated. Abnormal brain activity may precede vasodilation, but I think vasodilation is probably responsible for the painful part of the migraine attack. Caffeine tends to constrict blood vessels, which would seem to cause pain by cutting off blood flow. But mid-migraine, caffeine may relieve pain by returning enlarged and painfully distorted arteries back to their pain-free state.

Perhaps there's another explanation for caffeine's effect, but it's clear from experience that caffeine, especially in the form of coffee, helps many people with migraines. But there are individual differences — in migraine and in the response to caffeine. For some, caffeine triggers migraines.

If caffeine is pharmacologically complicated, that is true a hundred times over for coffee. Coffee is a stimulant for the brain and a diuretic. I have heard from patients with myasthenia gravis, a neurological disease with fluctuating levels of muscle fatigue, that a cup of coffee in the morning literally opens up their droopy eyes. Maybe it does that for some of the rest of us. And Paul Erdos, the quirky Hungarian mathematician, defined a mathematician as "a machine for turning coffee into theorems."

Notwithstanding the complexities of migraines and coffee, a temperate amount — say, one to three cups a day — can be an effective part of an anti-migraine program. — Edward Wolpow, M.D., Mount Auburn Hospital, Cambridge, MA

(C) 2010. PRESIDENT AND FELLOWS OF HARVARD COLLEGE. ALL RIGHTS RESERVED. DISTRIBUTED BY TRIBUNE MEDIA SERVICES.